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The ability to control the solid-statestructure of organic electronicmaterials can have a large effect on the quality of the devices towhich they are applied. In this paper, we describe the use of π–πinteractions to direct the crystal structure/solid-state arrangementof boron subphthalocyanine (BsubPc) derivatives by taking advantageof the π-electron-deficiency (π-acidity) of the BsubPcmolecular fragment. First, we outline why BsubPc is a π-acidby looking at its chemical characteristics and the structure of crystalsformed with other π-acidic moieties. Then we show how the solid-statearrangement of BsubPc can be purposefully altered by adding π-basicsubstituents. We found that adding a naphthoxy substituent providesan interaction that is strong enough to direct BsubPc into a novelsolid-state arrangement made up of ribbons (or catemers) of moleculeslinked through π-stacking interactions between the naphthoxyand neighboring BsubPc molecular fragments. A similar effect was alsoseen when the naphthoxy fragment was added to the stronger π-acidperfluoro-BsubPc (F12BsubPc). [ABSTRACT FROM AUTHOR]

Boronsubphthalocyanine (BsubPc) derivativesare materialsthat have recently seen an increase in attention, particularily forapplication as colorants and functional materials in organic electronicdevices. However, the solubilities of most BsubPcderivativesare too low to utilize solution-based processing techniques. Wherethere are derivatives that are soluble, they rely on the additionof large alkyl chains for solubilization the result of which is anincrease in the molecular weight and a decrease of the specific absorptivityof the BsubPc. In this paper we disclose the identityof two mass-efficient, highly soluble BsubPcderivatives:3-methylphenoxy-BsubPcand 3,4-dimethylphenoxy-BsubPc. We compare their solubilities and crystal packingstructures to previously known BsubPcderivatives. Weput forward a symmetry-based argument for the reason for their surprisinglyhigh solubility wherein we treat the molecules as two separate fragments:the phenoxy group and the BsubPcgroup. The symmetry-basedargument suggests that by ignoring the BsubPcfragmentcommon to each derivative a better estimate of the relative solubilitiescan be estimated through previously established empirical formulas. [ABSTRACT FROM AUTHOR]

The synthesis and study of a series of pseudohalides of boron subphthalocyanine (BsubPc) are reported. Each pseudohalide has been compared to the more common chloride and bromide of BsubPc, and we have found that most react slower under standard phenoxylation and hydrolysis conditions. Three pseudohalides (TsO-BsubPc, MsO-BsubPc, and BsO-BsubPc) do not hydrolyze at all even after prolonged periods of time in the presence of water. Single crystals of TsO-, MsO-, and ClsO-BsubPc were obtained, and their structures were unambiguously determined. [ABSTRACT FROM AUTHOR]

With the knowledge that the dominant photodynamic therapy (PDT) mechanism of 1a (WST09) switched from type 2 to type 1 for 1b (WST11) upon taurine-driven E-ring opening, we hypothesized that taurine-driven E-ring opening of bacteriochlorophyll derivatives and net-charge variations would modulate reactive oxygen species (ROS) photogeneration. Eight bacteriochlorophyll a derivatives were synthesized with varying charges that either contained the E ring (2a-5a) or were synthesized by taurine-driven E-ring opening (2b-5b). Time-dependent density functional theory (TDDFT) modeling showed that all derivatives would be type 2 PDT-active, and ROS-activated fluorescent probes were used to investigate the photogeneration of a combination of type 1 and type 2 PDT ROS in organic- and aqueous-based solutions. These investigations validated our predictive modeling calculations and showed that taurine-driven E-ring opening and increasing negative charge generally enhanced ROS photogeneration in aqueous solutions. We propose that these structure-activity relationships may provide simple strategies for designing bacteriochlorins that efficiently generate ROS upon photoirradiation.